/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include "md5.h"

/*
**************************************************************************
** md5.c -- the source code for MD5 routines				**
** RSA Data Security, Inc. MD5 Message-Digest Algorithm			**
** Created: 2/17/90 RLR							**
** Revised: 1/91 SRD, AJ, BSK, JT Reference C ver., 7/10 constant corr.	**
**************************************************************************
*/

/*
**************************************************************************
** Copyright (C) 1990, RSA Data Security, Inc. All rights reserved.	**
**									**
** License to copy and use this software is granted provided that	**
** it is identified as the "RSA Data Security, Inc. MD5 Message-	**
** Digest Algorithm" in all material mentioning or referencing this	**
** software or this function.						**
**									**
** License is also granted to make and use derivative works		**
** provided that such works are identified as "derived from the RSA	**
** Data Security, Inc. MD5 Message-Digest Algorithm" in all		**
** material mentioning or referencing the derived work.			**
**									**
** RSA Data Security, Inc. makes no representations concerning		**
** either the merchantability of this software or the suitability	**
** of this software for any particular purpose.  It is provided "as	**
** is" without express or implied warranty of any kind.			**
**									**
** These notices must be retained in any copies of any part of this	**
** documentation and/or software.					**
**************************************************************************
*/


/*
**************************************************************************
**  Message-digest routines:						**
**  To form the message digest for a message M				**
**    (1) Initialize a context buffer mdContext using MD5Init		**
**    (2) Call MD5Update on mdContext and M				**
**    (3) Call MD5Final on mdContext					**
**  The message digest is now in mdContext->digest[0...15]		**
**************************************************************************
*/

/* forward declaration */
static void Transform (UINT4 *buf, UINT4 *in);

static unsigned char PADDING[64] = {
	0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
	};

/* F, G, H and I are basic MD5 functions */
#define	F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define	G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define	H(x, y, z) ((x) ^ (y) ^ (z))
#define	I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits */
#define	ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4 */
/* Rotation is separate from addition to prevent recomputation */
#define	FF(a, b, c, d, x, s, ac) \
	{(a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}
#define	GG(a, b, c, d, x, s, ac) \
	{(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}
#define	HH(a, b, c, d, x, s, ac) \
	{(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}
#define	II(a, b, c, d, x, s, ac) \
	{(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}

/*
* The routine MD5Init initializes the message-digest context
* mdContext. All fields are set to zero.
*/
void MD5Init (MD5_CTX *mdContext)
{
	mdContext->i[0] = mdContext->i[1] = (UINT4)0;

	/*
	* Load magic initialization constants.
	*/
	mdContext->buf[0] = (UINT4)0x67452301;
	mdContext->buf[1] = (UINT4)0xefcdab89;
	mdContext->buf[2] = (UINT4)0x98badcfe;
	mdContext->buf[3] = (UINT4)0x10325476;
}

/*
* The routine MD5Update updates the message-digest context to
* account for the presence of each of the characters inBuf[0..inLen-1]
* in the message whose digest is being computed.
*/
void MD5Update (MD5_CTX *mdContext, unsigned char *inBuf, unsigned int inLen)
{
	UINT4 in[16];
	int mdi;
	unsigned int i, ii;

	/* compute number of bytes mod 64 */
	mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

	/* update number of bits */
	if ((mdContext->i[0] + ((UINT4)inLen << 3)) < mdContext->i[0])
		mdContext->i[1]++;
	mdContext->i[0] += ((UINT4)inLen << 3);
	mdContext->i[1] += ((UINT4)inLen >> 29);

	while (inLen--) {
		/* add new character to buffer, increment mdi */
		mdContext->in[mdi++] = *inBuf++;

		/* transform if necessary */
		if (mdi == 0x40) {
			for (i = 0, ii = 0; i < 16; i++, ii += 4)
				in[i] = (((UINT4)mdContext->in[ii+3]) << 24) |
					(((UINT4)mdContext->in[ii+2]) << 16) |
					(((UINT4)mdContext->in[ii+1]) << 8) |
					((UINT4)mdContext->in[ii]);
			Transform (mdContext->buf, in);
			mdi = 0;
		}
	}
}

/*
* The routine MD5Final terminates the message-digest computation and
* ends with the desired message digest in mdContext->digest[0...15].
*/
void MD5Final (MD5_CTX *mdContext)
{
	UINT4 in[16];
	int mdi;
	unsigned int i, ii;
	unsigned int padLen;

	/* save number of bits */
	in[14] = mdContext->i[0];
	in[15] = mdContext->i[1];

	/* compute number of bytes mod 64 */
	mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

	/* pad out to 56 mod 64 */
	padLen = (mdi < 56) ? (56 - mdi) : (120 - mdi);
	MD5Update (mdContext, PADDING, padLen);

	/* append length in bits and transform */
	for (i = 0, ii = 0; i < 14; i++, ii += 4)
		in[i] = (((UINT4)mdContext->in[ii+3]) << 24) |
			(((UINT4)mdContext->in[ii+2]) << 16) |
			(((UINT4)mdContext->in[ii+1]) << 8) |
			((UINT4)mdContext->in[ii]);
			Transform (mdContext->buf, in);

	/* store buffer in digest */
	for (i = 0, ii = 0; i < 4; i++, ii += 4) {
		mdContext->digest[ii] =
				(unsigned char)(mdContext->buf[i] & 0xFF);
		mdContext->digest[ii+1] =
			(unsigned char)((mdContext->buf[i] >> 8) & 0xFF);
		mdContext->digest[ii+2] =
			(unsigned char)((mdContext->buf[i] >> 16) & 0xFF);
		mdContext->digest[ii+3] =
			(unsigned char)((mdContext->buf[i] >> 24) & 0xFF);
	}
}

/*
* Basic MD5 step. Transforms buf based on in.
*/
static void Transform (UINT4 *buf, UINT4 *in)
{
	UINT4 a = buf[0], b = buf[1], c = buf[2], d = buf[3];

/* Round 1 */
#define	S11	7
#define	S12	12
#define	S13	17
#define	S14	22
	FF (a, b, c, d, in[ 0], S11, 3614090360U); /* 1 */
	FF (d, a, b, c, in[ 1], S12, 3905402710U); /* 2 */
	FF (c, d, a, b, in[ 2], S13,  606105819U); /* 3 */
	FF (b, c, d, a, in[ 3], S14, 3250441966U); /* 4 */
	FF (a, b, c, d, in[ 4], S11, 4118548399U); /* 5 */
	FF (d, a, b, c, in[ 5], S12, 1200080426U); /* 6 */
	FF (c, d, a, b, in[ 6], S13, 2821735955U); /* 7 */
	FF (b, c, d, a, in[ 7], S14, 4249261313U); /* 8 */
	FF (a, b, c, d, in[ 8], S11, 1770035416U); /* 9 */
	FF (d, a, b, c, in[ 9], S12, 2336552879U); /* 10 */
	FF (c, d, a, b, in[10], S13, 4294925233U); /* 11 */
	FF (b, c, d, a, in[11], S14, 2304563134U); /* 12 */
	FF (a, b, c, d, in[12], S11, 1804603682U); /* 13 */
	FF (d, a, b, c, in[13], S12, 4254626195U); /* 14 */
	FF (c, d, a, b, in[14], S13, 2792965006U); /* 15 */
	FF (b, c, d, a, in[15], S14, 1236535329U); /* 16 */

/* Round 2 */
#define	S21	5
#define	S22	9
#define	S23	14
#define	S24	20
	GG (a, b, c, d, in[ 1], S21, 4129170786U); /* 17 */
	GG (d, a, b, c, in[ 6], S22, 3225465664U); /* 18 */
	GG (c, d, a, b, in[11], S23,  643717713U); /* 19 */
	GG (b, c, d, a, in[ 0], S24, 3921069994U); /* 20 */
	GG (a, b, c, d, in[ 5], S21, 3593408605U); /* 21 */
	GG (d, a, b, c, in[10], S22,   38016083U); /* 22 */
	GG (c, d, a, b, in[15], S23, 3634488961U); /* 23 */
	GG (b, c, d, a, in[ 4], S24, 3889429448U); /* 24 */
	GG (a, b, c, d, in[ 9], S21,  568446438U); /* 25 */
	GG (d, a, b, c, in[14], S22, 3275163606U); /* 26 */
	GG (c, d, a, b, in[ 3], S23, 4107603335U); /* 27 */
	GG (b, c, d, a, in[ 8], S24, 1163531501U); /* 28 */
	GG (a, b, c, d, in[13], S21, 2850285829U); /* 29 */
	GG (d, a, b, c, in[ 2], S22, 4243563512U); /* 30 */
	GG (c, d, a, b, in[ 7], S23, 1735328473U); /* 31 */
	GG (b, c, d, a, in[12], S24, 2368359562U); /* 32 */

/* Round 3 */
#define	S31	4
#define	S32	11
#define	S33	16
#define	S34	23
	HH (a, b, c, d, in[ 5], S31, 4294588738U); /* 33 */
	HH (d, a, b, c, in[ 8], S32, 2272392833U); /* 34 */
	HH (c, d, a, b, in[11], S33, 1839030562U); /* 35 */
	HH (b, c, d, a, in[14], S34, 4259657740U); /* 36 */
	HH (a, b, c, d, in[ 1], S31, 2763975236U); /* 37 */
	HH (d, a, b, c, in[ 4], S32, 1272893353U); /* 38 */
	HH (c, d, a, b, in[ 7], S33, 4139469664U); /* 39 */
	HH (b, c, d, a, in[10], S34, 3200236656U); /* 40 */
	HH (a, b, c, d, in[13], S31,  681279174U); /* 41 */
	HH (d, a, b, c, in[ 0], S32, 3936430074U); /* 42 */
	HH (c, d, a, b, in[ 3], S33, 3572445317U); /* 43 */
	HH (b, c, d, a, in[ 6], S34,   76029189U); /* 44 */
	HH (a, b, c, d, in[ 9], S31, 3654602809U); /* 45 */
	HH (d, a, b, c, in[12], S32, 3873151461U); /* 46 */
	HH (c, d, a, b, in[15], S33,  530742520U); /* 47 */
	HH (b, c, d, a, in[ 2], S34, 3299628645U); /* 48 */

/* Round 4 */
#define	S41	6
#define	S42	10
#define	S43	15
#define	S44	21
	II (a, b, c, d, in[ 0], S41, 4096336452U); /* 49 */
	II (d, a, b, c, in[ 7], S42, 1126891415U); /* 50 */
	II (c, d, a, b, in[14], S43, 2878612391U); /* 51 */
	II (b, c, d, a, in[ 5], S44, 4237533241U); /* 52 */
	II (a, b, c, d, in[12], S41, 1700485571U); /* 53 */
	II (d, a, b, c, in[ 3], S42, 2399980690U); /* 54 */
	II (c, d, a, b, in[10], S43, 4293915773U); /* 55 */
	II (b, c, d, a, in[ 1], S44, 2240044497U); /* 56 */
	II (a, b, c, d, in[ 8], S41, 1873313359U); /* 57 */
	II (d, a, b, c, in[15], S42, 4264355552U); /* 58 */
	II (c, d, a, b, in[ 6], S43, 2734768916U); /* 59 */
	II (b, c, d, a, in[13], S44, 1309151649U); /* 60 */
	II (a, b, c, d, in[ 4], S41, 4149444226U); /* 61 */
	II (d, a, b, c, in[11], S42, 3174756917U); /* 62 */
	II (c, d, a, b, in[ 2], S43,  718787259U); /* 63 */
	II (b, c, d, a, in[ 9], S44, 3951481745U); /* 64 */

	buf[0] += a;
	buf[1] += b;
	buf[2] += c;
	buf[3] += d;
}
